Direct torque flow constant velocity joint face spline connector

ABSTRACT

A direct torque flow constant velocity joint connector includes an outer joint part, and inner joint part, a cage and a plurality of balls. The outer joint part includes outer ball tracks. The inner joint part includes inner ball tracks and a rotational axis, wherein the inner joint part has a face spline oriented about the rotational axis. The plurality of balls are provided in the cage and engage the inner and outer ball tracks of the respective inner and outer joint parts, thereby allowing torque transmission by way of the face splines. Also provided is a direct torque flow constant velocity joint connection.

TECHNICAL FIELD

The present invention relates generally to motor vehicle shaft joints,and more particularly concerns a direct torque flow constant velocityjoint having a face spline connection.

BACKGROUND ART

Constant velocity joints connecting shafts to drive units are commoncomponents in automotive vehicles. The drive unit typically has anoutput shaft or an input shaft for receiving the joint. Typically, thedrive unit is an axle, transfer case, transmission, power take-off unitor other torque device, all of which are common components in automotivevehicles. Typically, one or more joints are assembled to the shaft toform a propeller or drive shaft assembly. It is the propeller shaftassembly, which is connected, for instance, at one end to an outputshaft of a transmission and, at the other end, to an input shaft of adifferential. The shaft is solid or tubular with ends adapted to attachthe shaft to an inner race of the joint thereby allowing an outer raceconnection to a drive unit. The inner race of the joint is typicallypress-fit, splined, or pinned to the shaft making the outer race of thejoint available to be bolted or press-fit to a hub connector, flange orstubshaft of the particular drive unit. At the other end of thepropeller shaft, the same typical or traditional connection is made to asecond drive unit when connecting the shaft between the two drive units.Connecting the shaft to a drive unit via the constant velocity joint(CVJ) in this manner is considered a traditional connection. Directtorque flow (DTF) connection is a newer connection style that hasadvantages and improvements over the traditional connection.

A DTF connection differs from a traditional connection in that the outerrace is connected to the shaft that extends between different joints,and the inner race is connectable to the drive unit. One example of aDTF connection provides that the outer race of a CVJ is friction weldedto a propeller shaft and the inner race of the CVJ includes a femalespline that is connectable to a journal shaft of a transmission.Typically, the inner race of the CVJ is rotationally securable fortorque transmission to the journal shaft by an axial spline and isaxially retained thereto by a spring clip, a circlip or a threaded nut.However, while the splined connection is secured in the axial direction,the connection does not prevent radial and axial movement. Moreover, theaxial spline may allow for undesirable debris and corrosion therein,making disassembly difficult and reducing the life expectancy of thedrive shaft assembly.

It is desirable to have a DTF CVJ that overcomes the limitationsindicated above. Moreover, it is desirable to have a DTF CVJ thatprovides for a connection to a drive unit while reducing axial andradial movement. Furthermore, it would be desirable to provide a DTF CVJthat improves installation or disassembly.

DISCLOSURE OF THE INVENTION

Accordingly, the present invention provides a direct torque flowconstant velocity joint having a face spline connector. The face splineconnector minimizes axial and radial movement. In addition, the facespline connector is directly securable to a mating end of a drive unitthereby improving installation or disassembly.

Specifically, a direct torque flow constant velocity joint connectorincludes an outer joint part, an inner joint part, a cage and aplurality of balls. The outer joint part includes outer ball tracks. Theinner joint part includes inner ball tracks and a rotational axis,wherein the inner joint part has a face spline oriented about therotational axis. The plurality of balls are provided in the cage andengage the inner and outer ball tracks of the respective inner and outerjoint parts, thereby allowing torque transmission by way of the facesplines.

The present invention will be best understood by reference to thefollowing detailed description and taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

For a more complete understanding of this invention, reference shouldnow be made to the embodiments illustrated in greater detail in theaccompanying drawings and described below by way of examples of theinvention.

FIG. 1 shows a plan view of an exemplary drive system for a typicalfour-wheel drive automobile.

FIG. 2 shows a cross-sectional view of a first embodiment of a DTF CVJhaving a face spline connector.

FIG. 3 shows an axial view of the face spline connector shown in FIG. 2.

FIG. 4 shows a cross-sectional view of a second embodiment of a DTF CVJhaving a face spline connector.

FIG. 5 shows an axial view of a third embodiment of an inventive DTF CVJhaving a face spline connector.

DETAILED DESCRIPTION

In the following description, various operating parameters andcomponents are described for one or more constructed embodiments. Thesespecific parameters and components are included as examples and are notmeant to be limiting.

While the invention is described with respect to a DTF CVJ having a facespline connector, the following apparatus is capable of being adaptedfor various connecting purposes including automotive vehicle driveaxles, motor systems that use a propeller shaft, or other vehicles andnon-vehicle applications which require propeller shaft assemblies fortorque transmission.

An exemplary drive system 12 for a typical four-wheel drive automobileis shown in FIG. 1. While a four-wheel drive system is shown anddescribed, the concepts here presented could apply to a single driveunit system or multiple drive unit systems, including rear wheel driveonly vehicles, front wheel drive only vehicles, all wheel drivevehicles, and four-wheel drive vehicles. In this example, the drivesystem 12 includes an engine 14 that is connected to a transmission 16and a power take-off unit 18. A front differential 20 has a right handside half shaft 22 and left hand side half shaft 24, each of which areconnected to a wheel and deliver power to the wheels. On both ends ofthe right hand side half shaft 22 and left hand side half shaft 24 areconstant velocity joints 10. A propeller shaft 26 connects the frontdifferential 20 to a rear differential 28 wherein the rear differential28 includes a rear right hand side shaft 30 and a rear left hand sideshaft 32, each of which ends with a wheel on one end thereof. Constantvelocity joints 10 are located on both ends of the half shafts 30, 32that connect to the wheels and the rear differential 28. The propellershaft 26, shown in FIG. 1, is a three-piece propeller shaft thatincludes a plurality of Cardan joints 34 and one high-speed constantvelocity joint 10. The propeller shaft 26 includes interconnectingshafts 23, 25, 27. The constant velocity joints 10 transmit power to thewheels through the propeller shaft 26 even if the wheels or thepropeller shaft 26 have changed angles due to steering, raising, orlowering of the suspension of the vehicle. The constant velocity joints10 may be any of the standard types known, such as a plunging tripod, across groove joint, a fixed ball joint, a fixed tripod joint, or adouble offset joint, all of which are commonly known terms in the artfor different varieties of constant velocity joints 10. The constantvelocity joints 10 allow for transmission of constant velocities atangles typically encountered in every day driving of automotive vehiclesin both the half shafts, interconnecting shafts and propeller shafts ofthese vehicles. Optionally, each Cardan joint 34 may be replaced withany other suitable type of joint, including constant velocity jointtypes. The shafts 22, 23, 24, 25, 27, 30, 32 may be solid or tubularwith ends adapted to attach each shaft to an inner race or an outer raceof a joint in accordance with a traditional connection, thereby allowingthe outer race or inner race to be connected to a hub connector 36, aflange 38 or stubshaft 40 of each drive unit, as appropriate, for theparticular application. Thus, any of the traditional connectionsidentified in FIG. 1 at 10 or 34 may be direct torque flow constantvelocity joint (DTF CVJ) having a face spline connector in accordancewith a first embodiment (FIG. 2), a second embodiment (FIG. 4) or athird embodiment (FIG. 5) of the invention.

For completeness of the description of the first, second and thirdembodiments of the invention as given in FIGS. 2, 4 and 5, the termdirect torque flow (DTF) connection refers to a connection from theinner race of a constant velocity joint (CVJ) to the shaft of adifferential, transmission or transfer case, generally supplied by thecustomer. Thus, a DTF connection refers to the inner race coupling tothe shaft of a drive unit, such as a differential, transmission ortransfer case without limitation, as opposed to the traditionalconnection mentioned above.

Also, as used herein, a DTF connector refers to a joint coupled to ashaft that forms a DTF shaft assembly. Only together with the shaft of adifferential, for example, does a DTF connector combine to make a DTFconnection. It is recognized that the shaft of the drive unit mayinclude the shaft of any input or output drive unit and is notnecessarily limited to a shaft of a differential, transmission ortransfer case.

FIGS. 2 and 4 will initially be described jointly below to the extentthat their details generally correspond to one another. However, each ofthe constant velocity joints given in the various embodiments of theinvention may have additional or different features recognized by aperson of skill in the art. FIGS. 2 and 4 each show a CVJ 50, 150,respectively, for connection, but only FIG. 2 includes a journal shaft52 of a drive unit 51 coupled to the CVJ 50 and axially retained by acompression bolt 54 axially securing the shaft 52 to the CVJ 50.Generally, each CVJ 50, 150 includes an outer joint part 60, 160, aninner joint part 62, 162 having an attachment surface 67, 167, torquetransmitting balls 63, 163, and a ball cage 64, 164, respectively. Theballs 63, 163 are held in windows within the ball cage 64, 164,respectively. A boot assembly 70, 170 may be included to seal each CVJ50, 150 between the inner joint part 62, 162, and the outer joint part60, 160, respectively. Also, each CVJ 50, 150 may utilize one of theinventive face spline connectors 100, 200, respectively, to be describedbelow. Before turning to the discussion of each inventive face splineconnector, the representative constant velocity joint 50 given in FIG. 2is first discussed.

The outer joint part 60 generally has a circumferential-shaped orsemi-spherical bore therein and an outer surface. The outer joint part60 is generally made of a steel material, however, it should be notedthat any other type of metal material, hard ceramic, plastic, orcomposite material, etc. may also be used for the outer joint part 60.The material is required to be able to withstand the high speeds,temperatures and contact pressures required for the CVJ 50. The outerjoint part 60 also includes a plurality of axially opposed ball trackslocated on an inner surface thereof. The tracks generally form aspherical-shaped path within the inner surface of the outer joint part60. The tracks are axially opposed such that one half of the ball tracksopen to a side of the outer joint part 60 opposite to that of the otherhalf of the ball tracks in any number of patterns. Optionally, fordifferent types of CVJs, the ball tracks all may open or axially alignon the same side of the outer race. Also, the ball tracks may be of agothic or elliptical shape provided the pressure angle and conformityare maintained, or may be other shapes, as is understood by a personhaving skill in the art. It should be noted that in the first embodimentas shown in FIG. 2 is a four plus four constant velocity joint, whichhas a total of eight balls in the CVJ 50. While the CVJ 50 firstembodiment is a DTF CVJ having a fixed CVJ arrangement, any constantvelocity joint type may, be utilized. Further, it is recognized the CVJmay be a fixed or plunging CVJ, including without limitation a VL, RF,AC, DO, or tripod joints including other fixed or plunging CVJs.However, it should be noted that it is also contemplated that a jointmay be made having any number of balls incorporating all of the featuresof the CVJ 50 according to the present invention.

The inner joint part 62 of the present embodiment generally has acircumferential shape. The inner joint part 62 is arranged within a boreof an outer joint part 60. An attachment or outer surface 67 of theinner joint part 62 includes a plurality of ball tracks that are axiallyopposed. The ball tracks generally have a spherical shape and arealigned with the ball tracks on the outer joint part 60 such that theaxial angle will open in a similar or the same direction as the balltrack directly aligned above it on the outer joint part 60. The balltracks on the outer spherical surface of the inner joint part 62 haveone half of the ball tracks axially oriented in one way while the otherhalf of the ball tracks are axially oriented in the opposite direction.The ball tracks will open in an alternating pattern around the outercircumference of the inner joint part 62 in a matching relationship tothat of the ball tracks of the outer joint part 60. It should be notedthat in this embodiment the inner joint part 62 is made of steel,however, any other metal composite, hard plastic, ceramic, etc. may alsobe used.

The ball cage 64 generally has a ring-like appearance. The ball cage 64is arranged within the bore of the outer joint part 60 such that it isnot, in this embodiment, in contact with the inner surface of the outerjoint part 60. The cage 64 has a plurality of oblong-shaped orifices orwindows through a surface thereof. The number of windows may match thenumber of ball tracks on the outer joint part 60 and inner joint part 62of the CVJ 50, which is eight windows therethrough in the presentembodiment of the invention. The number of balls and windows may,however, differ. The cage 64 along with the inner joint part 62 arepreferably made of a steel material but any other hard metal material,plastic, composite or ceramic, etc. may also be used.

The constant velocity joint 50 includes a plurality of balls 63. Theballs 63 are each arranged within one or more windows of the cage 64 andwithin a ball track of the outer joint part 60 and of the inner jointpart 62, respectively. More than one ball may be arranged within each ofthe windows or there may be no balls within a window. Therefore, theballs 63 will be capable of rolling in the axially opposed tracksaligned in the same direction.

The CVJ 50 may include a grease cap or barrier 57. The barrier isgenerally made of a metal material, however, any plastic, rubber,ceramic or composite material may also be used. The barrier is press fitor integrally constructed between the outer joint part 60 and thepropeller shaft or between the inner joint part 62 and a journal shaft52. However, any other securing method known may also be used such asfasteners, bonding, etc. The barrier will insure the grease, which isused as a lubricant, will remain within the CVJ 50. Optionally, a ventport 59 may be placed through the barrier or the outer joint part 60 torelieve, any internal pressure within the CVJ 50, and the vent port mayinclude a valve.

The boot assembly 70 includes a boot cover or shroud 72 and a reversedinternal radius diaphragm or rolling radial boot 74 that rolls outwardlyfrom an attached CVJ 50. The boot assembly 70 is connected to a CVJ 50for providing a protective barrier for the internal parts andlubrication retention therein. It is recognized that other types of bootassemblies would also be suitable for providing the protective barrier.

The boot 74 includes a compression section 80 at one end and anattachment section 82 at the other end. The first section 80 of the boot74 is connected directly to the outer joint part 60 and further retainedthereto by the shroud 72. Optionally, the first section 80 of the boot74 is attached to the shroud 72, thereby being connectable, directly orindirectly, to the outer joint part 60. The second section 82 of theboot 74 is connected to an attachment surface 67 of an inner joint part62 by resilient retention of the boot material, or by an optionalretaining band or other fastener 76, and completes a sealed environmentin the CVJ 50. The boot 74 may also include a compression lip 81annularly extending around the first section 80 of the boot 74 toenhance the seal between the boot assembly 70 and the outer joint part60.

The boot 74 may comprise any suitable material that is sufficientlyflexible to allow the CVJ 50 to operate through a wide range of angles.Suitable materials include thermoplastic, rubber, silicone, plasticmaterial and urethane, etc. Thermoplastic, rubber and silicone alsoprovide good sealing properties for the boot 74.

The shroud 72 is generally annular having a compression portion 90 and afree portion 92 separated by a support portion 98 in the form of anaxially extending flange. The compression portion 90 is for annularlyreceiving the boot 74 and sealingly connecting it to CVJ 50. In thisembodiment, the compression portion 90 is crimped within acircumferential channel 65 located in the exterior of the outer jointpart 60 of the CVJ 50. Also, the compression portion 90 may include acompression crease 96 that provides for additional compressive retentionof compression lip 81 of the boot 74 against a recess 66 of the outerjoint part 60 of the CVJ 50. The free portion 92 may also include anannular flare 94, which serves as a protective device for deflectingoutside debris while supporting and retaining the boot 74. Moreover, thesupport portion 98 stabilizes the reversed internal radius diaphragm orrolling radial boot 74 by radially retaining the boot within the shroud72 when the CVJ 50 undergoes angular and cyclic gyrations duringoperation. Generally, the shroud 72 provides protection to the boot 74by minimizing external impact from debris.

The support portion 98 of the shroud 72 supports and radially retainsthe boot 74 as it is received during all angular displacements caused bythe CVJ 50, while the free portion 92 only supports and radially retainsthe boot 74 as it rolls onto the second portion 92 caused by largeangular displacements of the CVJ 50. Primarily, it is the free or openend of the second portion 92 of the shroud 72 that provides shielding orbarrier for the boot 74 from external debris. The shroud 72 may be madefrom metal or other materials, including plastic, for example, that havea rigid quality when used as a substantially cylindrical shape. For theshroud 72 of this embodiment, it is beneficial to use a suitablematerial in the compression or first portion 90 that is also deformableto provide the required retention force when crimping the assembly 70 tothe CVJ 50.

While the first embodiment of the invention is described for aparticular CVJ having balls and sets of ball tracks for a particulartype of constant velocity joint motion, it is recognized that any othersuitable constant velocity balls and sets of ball tracks may be utilizedwith the current invention to advantage. Moreover, the CVJ may also beof the fixed or plunging type of joint as is recognized within the art.Because CVJs are well understood to a person of skill in the art, theCVJs as given in the second and third embodiments are discussed below tothe extent necessary to present the various embodiments of theinvention.

FIG. 2 shows a first embodiment of an inventive DTF CVJ 50 having a facespline connector 100 shown being used to advantage with a mating end 53of a supplied shaft 52 of a drive unit 51. FIG. 3 shows an axial view ofthe face spline connector 100 shown in FIG. 2. The spline connector 100is an axial extension of the inner joint part, 62, which includes inthis embodiment an inner bore having threads 55 for receiving thecompression bolt 54.

The face spline connector 100 allows the constant velocity joint 50 tobe secured to the mating end 53 of the shaft 52 via face splines locatedon both an end of the shaft 52 and an end of the inner joint part 62.The face spline connector 100 generally has the appearance of aplurality of predefined teeth 102 that have specific heights and anglededges to allow for a secure connection between the inner joint part 62and the shaft 52 while also reducing any noise or vibration that mightbe caused between a toothed connection in the constant velocity joint50. As mentioned above, the shaft 52 is connected to the inner jointpart 62 by the bolt 54 engaging inner threads 55 of the inner joint part62. The plurality of teeth 102 are located on the face of each of theinner joint part 62 and the shaft 52 and are arranged at the outerperiphery of both the inner joint part 62 and the shaft 52. The teeth102 may be a continuous row of teeth 102 around the entire outerperiphery or the teeth 102 may include predetermined gaps 104 built intothe teeth 102, for less weight and easier mounting. The teeth 102 onboth the inner joint part 62 and the shaft 52 in the embodiment showngenerally have a square shaped tooth 102, however any other shaped toothmay be used depending on the design requirements of the constantvelocity joint 50. Therefore, the teeth 102 on the inner joint part 62will engage with the teeth 102 on the shaft 52 and create a rotateablyfixed connection between the inner joint part 62 and the shaft 52 whichwill allow for rotational torque to be transferred through the constantvelocity joint 50. Hence, it should be noted that different heights,widths and angles may be used on the teeth 102 of both the inner jointpart 62 and the shaft 52 which will allow for specific torque transfercapabilities to be designed into the constant velocity joint 50according to the invention.

To improve alignment accuracy, the plurality of teeth 102 and/or thepredetermined gaps 104 may include a pressure angle θ. The pressureangle θ extends from a rotational axis 108 outwardly through theplurality of teeth and/or predetermined gaps to the outer peripherythereof, thereby improving alignment and centering of the inner jointpart 62 when connected to the shaft 52. In this embodiment, the pressureangle θ extends axially outward. It is recognized the pressure angle θmay optionally extend axially inward, may be concave or convex, or maybe perpendicular to the rotational axis 108.

As previously mentioned, axial retention of the inner joint part 62 withthe shaft 52 is by way of a compression bolt 54. Axial retention of theinner joint part 60 with the shaft 52 may be accomplished in other waysas would be recognized by a person of skill in the art. It is alsorecognized that axial retention of the inner joint part 62 with a shaft52 may also be accomplished by a union, a nut, or other fastener just toname a few examples, without limitation.

FIG. 4 shows a second embodiment of an inventive DTF CVJ 150 having aface spline connector 200. The spline connector 200 includes in thisembodiment outer threads 155 located on the attachment surface 167 forreceiving a compression nut (not shown). The face spline connector 200allows the constant velocity joint 150 to be secured to a suppliedshaft. The face spline connector 200 generally has the appearance of aplurality of predefined teeth 202 that have specific heights and anglededges to allow for a secure connection between the inner joint part 162and the supplied shaft. The plurality of teeth 202 are located on theface of the inner joint part 162 and are arranged at the outer peripheryof the inner joint part 162. The spline connector 200 may be acontinuous row of teeth 202 around the entire outer periphery or theteeth 202 may include predetermined gaps 204 built into the teeth 202.The teeth 202 on the inner joint part 162 in this embodiment are showngenerally as U-shaped, however any other shaped tooth may be useddepending on the design requirements of the constant velocity joint 150.

FIG. 5 shows an axial view of a third embodiment of a DTF CVJ 250 havinga face spline connector 300. The face spline connector 300 of thisembodiment generally has the appearance of a plurality of predefinedteeth 302, 303 that have specific heights and angled edges to allow fora secure connection between the inner joint part 262 and a suppliedshaft. The plurality of teeth 302, 303 are located on the axially flatface of the inner joint part 262 and are arranged at the outer peripheryof the inner joint part 262. The spline connector 300 may includealternating rows of teeth 302, 303 and rows of gaps 304, 305, each rowarranged on quadrants located on the outer periphery of the inner jointpart 262. The teeth 302, 303 and the gaps 304, 305 on the inner jointpart 262 in this embodiment are shown generally a$ straight rectangularshaped, however any other shaped tooth may be used depending on thedesign requirements of the constant velocity joint 250. The teeth 302,303 and the gaps 304, 305 of this embodiment, are resultantly obtainedby a two-step broaching process wherein a first radial pass of the innerjoint part 262, the teeth 302 and the gaps 304 are formed in a firstdirection, and in a second radial pass of the inner joint part 262, theteeth 303 and the gaps 305 are formed in a second direction. However,any other manufacturing process may be used in other ways as would berecognized by a person of skill in the art.

While the material and manufacture of the some of CVJ parts have beendiscussed, appropriate selection for other parts would be wellunderstood by a person of skill in the art.

From the foregoing, it can be seen that there has been brought to theart a new and improved direct torque flow constant velocity joint. Whilethe invention has been described in connection with one or moreembodiments, it should be understood that the invention is not limitedto those embodiments. On the contrary, the invention covers allalternatives, modifications, and equivalents as may be included withinthe spirit and scope of the appended claims.

1. A direct torque flow constant velocity joint connector comprising: anouter joint part having outer ball tracks; an inner joint part havinginner ball tracks and a rotational axis; a cage; and a plurality ofballs provided in said cage and engaging said inner and outer balltracks, wherein said inner joint part includes a face spline about saidrotational axis and said face spline is oriented on said inner jointpart at a pressure angle.
 2. The connector of claim 1 wherein said innerjoint part includes an axial extension having said face spline.
 3. Theconnector of claim 1 wherein said inner joint part includes an innerbore having threads adapted to engage a compression bolt.
 4. Theconnector of claim 1 wherein said face spline includes a plurality ofpredefined teeth.
 5. The connector of claim 4 wherein said predefinedteeth are symmetrically located about said rotational axis.
 6. Theconnector of claim 4 wherein said predefined teeth are square shapedadapted to engage corresponding teeth of a drive shaft.
 7. The connectorof claim 4 wherein said predefined teeth are located on an outerperiphery of said inner joint part.
 8. The connector of claim 1 whereinsaid face spline includes a plurality of predetermined gaps.
 9. Theconnector of claim 8 wherein said predetermined gaps are symmetricallylocated about said rotational axis.
 10. The connector of claim 1 whereinsaid pressure angle extends from said rotational axis outwardly througha plurality of teeth or a plurality of gaps located in said face spline.11. The connector of claim 10 wherein said pressure angle extendsaxially outward.
 12. The connector of claim 10 further comprising a bootassembly providing a protective barrier between said inner joint partand said outer joint part.
 13. A direct torque flow constant velocityjoint having a face spline connector comprising: an outer joint parthaving outer ball tracks; an inner joint part having inner ball tracks,an axial extension and a face spline oriented about a rotational axis ata pressure angle on said axial extension; a cage; a plurality of ballsprovided in said cage and engaging said inner and outer ball tracks; anda boot assembly providing a protective barrier between said inner jointpart and said outer joint part.
 14. The connector of claim 13 whereinsaid axial extension includes an outer surface having external threadsfor retaining said inner joint part to a drive shaft.
 15. The connectorof claim 13 wherein said face spline includes a plurality of teeth andor a plurality of gaps.
 16. The connector of claim 13 wherein said facespline includes a plurality of teeth and a plurality of gapssymmetrically arranged around a face periphery of said inner joint part,wherein said teeth and said gaps are U-shaped.
 17. The connector ofclaim 13 wherein said pressure angle is concave and extends from saidrotational axis outwardly through a plurality of teeth or a plurality ofgaps located in said face spline.
 18. The connector of claim 13 whereinsaid face spline includes a plurality of straight teeth arranged inquadrants.
 19. An assembly comprising: an outer joint part having outerball tracks; an inner joint part having a rotational axis, inner balltracks and a joint face spline oriented about said rotational axis at apressure angle; a cage; a plurality of balls provided in said cage andengaging said inner and outer ball tracks; a boot assembly coupledbetween said inner joint part and said outer joint part; and a driveunit having a journal shaft having a mating face spline coupled to saidjoint face spline of said inner joint part.